Varying diameter catheter distal end design for decreased distal hub size

Abstract

This disclosure is directed to a catheter having a basket-shaped electrode assembly with a high electrode density. The basket-shaped electrode assembly may have a plurality of spines, such as up to twelve, each with a plurality of electrodes, such as up to sixteen. The distal ends of the plurality of spines are joined at a distal hub, all of which are fashioned from a single piece of superelastic material.

What is claimed is: 
     
       1. A catheter comprising:
 an elongated catheter body extending along a longitudinal axis, the elongated catheter body having a proximal end and a distal end;
 a flexible wire assembly positioned at the distal end of the elongated catheter body formed from a single piece of shape memory material, the flexible wire assembly having a plurality of spines, each spine having a proximal end and a distal end, each distal end extending from a distal hub having a stress-relieving edge; 
 a plurality of electrodes and cabling attached to each spine, the plurality of electrodes and cabling having a corresponding plurality of wires coiled on a core and covered by a sheath such that each electrode is attached through the sheath to one of the plurality of wires, such that the catheter has one operational state wherein the spines bow radially outwardly from the distal hub and another operational state wherein the spines are arranged generally along a longitudinal axis of the catheter body. 
 
 
     
     
       2. The catheter of  claim 1 , wherein the stress-relieving edge comprises a scalloped edge. 
     
     
       3. The catheter of  claim 1 , wherein the stress-relieving edge comprises a saw-toothed edge. 
     
     
       4. The catheter of  claim 1 , wherein the single piece of shape memory material comprises a nitinol alloy tube. 
     
     
       5. The catheter of  claim 4 , wherein the distal hub has a height that is approximately equal to a thickness of the nitinol alloy tube. 
     
     
       6. The catheter of  claim 4 , wherein the distal hub has a height that is approximately equal to two times the thickness of the nitinol alloy tube. 
     
     
       7. The catheter of  claim 1 , wherein the single piece of shape memory material comprises a sheet of nitinol alloy. 
     
     
       8. The catheter of  claim 1 , wherein the flexible wire assembly comprises at least six spines. 
     
     
       9. The catheter of  claim 1 , wherein the flexible wire assembly comprises at least ten spines. 
     
     
       10. The catheter of  claim 1 , wherein the flexible wire assembly comprises at least twelve spines. 
     
     
       11. The catheter of  claim 1 , wherein each spine comprises at least eight electrodes. 
     
     
       12. The catheter of  claim 1 , wherein each spine comprises at least sixteen electrodes. 
     
     
       13. The catheter of  claim 1 , wherein the catheter body has a diameter less than approximately 10 french and the flexible wire assembly comprises at least twelve spines, each spine having at least sixteen electrodes. 
     
     
       14. The catheter of  claim 1 , wherein the catheter body further comprises a lumen configured to deliver irrigation fluid to the flexible wire assembly. 
     
     
       15. A method for forming a catheter comprising:
 forming an elongate catheter body; 
 forming a plurality of spines and a connecting distal hub from a single piece of shape memory material, each spine having a proximal end and a distal end, each distal end extending from the distal hub; 
 forming a stress-relieving edge onto a distal end of the distal hub at a location opposite of the plurality of spines; 
 heating the flexible wire assembly to heat set a basket-shaped arrangement; 
 connecting a plurality of electrodes and cabling to each of the plurality of spines to form a basket-shaped electrode assembly, the plurality of electrodes and cabling having a corresponding plurality of wires coiled on a core and covered by a sheath such that each electrode is attached through the sheath to one of the plurality of wires, such that the catheter has one operational state wherein the spines bow radially outwardly from the distal hub and another operational state wherein the spines are arranged generally along a longitudinal axis of the catheter body; and 
 connecting the basket shaped electrode assembly to a distal end of the elongate catheter body. 
 
     
     
       16. The catheter of  claim 15 , wherein the single piece of shape memory material comprises a nitinol alloy tube. 
     
     
       17. The catheter of  claim 16 , wherein the distal hub has a height that is approximately equal to a thickness of the nitinol alloy tube. 
     
     
       18. The catheter of  claim 15 , wherein the single piece of shape memory material comprises a sheet of nitinol alloy. 
     
     
       19. The catheter of  claim 15 , wherein the stress-relieving edge is a scalloped edge.